1. Field of the Invention
The invention relates to an improved nail fastener for boarding and particularly to a fastener adopted for use on fragile boards and panels such as gypsum boards.
2. Description of the Prior Art
Conventional construction boards 61 and panels 62 (as shown in FIGS. 4 and 5) that have a relatively high density but do not have great strength such as gypsum boards are prone to crack when being nailed directly by a nail fastener 51. To remedy this disadvantage, a boarding fastener 71 has been developed in the industry (as shown in FIG. 6). The boarding fastener 71 includes a shank 711 and a blade 712. The shank 711 has a top end forming a flange 713 and a screw thread section formed on the peripheral surface, and a substantially cross shaped through hole 714 formed in the center. The blade 712 is formed by extending a conical front end of the shank that being cut to form a pair of V-shaped nibs. Such a structure can decrease the damage that might otherwise incur to the gypsum board 81 when the nail is hit into the gypsum board 81. However, there are still shortcomings when it is put to practical use, notably:
When the blade 712 on the nail nib is wedged into the board 81, the blade 712 can perform drill function and discharge debris being generated from the drilling board. The debris is almost being discharged completely without remaining in the fastener 71. As a result, the wedging of the fastener 71 in the board 81 becomes too loose, and the bonding strength between the fastener 71 and the board 81, and between the screw 72 and the fastener 71 are not stronger enough. The fastening is not firm or secured. It could result in poor construction quality.
In view of aforesaid disadvantages, the primary object of the invention is to provide an improved fastener for boarding that has at least two debris troughs forming on the shank of the fastener and extending to the screw thread section and a through hole formed in the rear section of the debris troughs running through a center hole of the fastener so that a portion of the debris is discharged while a portion of th debris is retained in the fastener and the center hole, thereby the fastener can be fastened to the board firmly and securely without loosening or causing fractures or cracks on the board.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.